Ultra-deep Subwavelength Confinement Palladium-Based Elliptical Cylinder Plasmonic Waveguide in the Near-Infrared Range

Ultra-deep subwavelength confinement and long propagation length are of large importance for compact photonic integration. Nevertheless, the subwavelength confinement ability of near-infrared (NIR) devices is continually appeared via the intrinsic Ohmic loss. In this study, a palladium-based elliptical cylinder plasmonic waveguide (PECPW) has proposed to achieve excellent propagating efficiency in the NIR ranges. The PECPW structure is composite of an elliptical cylinder palladium (Pd) nanowire and two dielectric layers as clothing. Here, the characteristics of the proposed waveguide on the wavelength of incident field and thickness of the low-index dielectric and high-index layers are investigated by using the finite element method. Our finding has shown that the proposed waveguide has a normalized mode area of ∼ 10 - 4 , figure of merit over 8000, and a propagation length over 270 μ m by tuning the semi-major axis Pd nanowire, wavelength of incident light, and the thickness of the dielectric layers. Hence, proposed waveguide illustrates lower loss and stronger surface plasmon polariton mode confinement than the similar plasmonic waveguides. Owing to these results, the designed structure could be used to the nanophotonic integrated circuits.